【作者】 刘三军；

【导师】 覃文庆；

【作者基本信息】 中南大学 ， 矿物加工工程， 2012， 博士

【摘要】 本论文设计并合成了七种羟肟酸类捕收剂；通过单矿物浮选试验,查明了合成药剂对一水硬铝石和高岭石的捕收行为；通过动电位测试、红外光谱测试、浮选溶液化学计算、量子化学计算和分子动力学模拟等手段探讨了羟肟酸与一水硬铝石和高岭石的作用机理,分析确定了羟肟酸分子系列与其浮选性能之间的关系。主要内容如下：(1)一水硬铝石主要沿(001)晶面解离,亲水性较强；高岭石沿(001)晶面完全解离,沿(110)与(010)晶面不完全解理,也有较强亲水性。一水硬铝石和高岭石的荷电机理相似,主要由断裂晶面对H+的吸附或解离引起,且电荷随pH不断变化；此外金属离子的晶格取代使高岭石的层面荷永久负电。(2)捕收剂的极性基团设计以O为主体；选定捕收剂的极性基为氧肟基,即-CONHOH型,非极性基碳量长6-9,非极性基有苯环、环烷和烷基。以羧酸脂、甲酸、盐酸羟胺为原料,采用羧酸脂-羟胺合成法,合成出7种羟肟酸化合物,合成产率较高,纯度大于90%。(3)单矿物浮选实验研究铝土矿正浮选体系中,羟肟酸系列药剂对一水硬铝石的捕收能力比较如下：壬烷羟肟酸>辛烷羟肟酸>(油酸)>己烷羟肟酸>环己烷羟肟酸>水杨羟肟酸>苯甲羟肟酸,羟肟酸系列药剂对高岭石的捕收能力比较如下：壬烷羟肟酸>(油酸)>辛烷羟肟酸>己烷羟肟酸>环己烷羟肟酸>水杨羟肟酸>苯甲羟肟酸。综合比较后选择辛烷羟肟酸作为铝土矿正浮选的主要捕收剂,其选择性和捕收能力优于油酸。硅酸钠、焦磷酸钠、氟硅酸钠和六偏磷酸钠四种抑制剂,对一水硬铝石浮选的影响都较小,四种抑制剂都能有效抑制高岭石、伊利石、叶腊石,其中以六偏磷酸钠的抑制效果最好。辛烷羟肟酸-油酸混合药剂体系中,总浓度为10-4mol×·L-1,辛烷羟肟酸占60%时,混合用药对于一水硬铝石回收率的提高尤为明显。(4)羟肟酸系列药剂与一水硬铝石和高岭石的作用机理：羟肟酸阴离子与一水硬铝石、高岭石表面的铝离子产生化学键作用,其作用方式属于化学吸附。羟肟酸阴离子吸附在铝硅矿物表面,能降低表面电位。C8在一水硬铝石表面产生了多层吸附,其吸附量大于在高岭石表面以单层吸附的吸附量。量子计算结果表明,非极性基种类对羟肟酸分子及离子的氧原子电荷影响较小,但非极性基种类对羟肟酸分子及离子的前线分子轨道能量差有一定影响。化学反应活性顺序为：苯甲酸>环己烷羧酸≈庚酸,疏水能力大小顺序为：庚酸>环己烷羧酸>苯甲酸。(5)人工混合矿及实际矿石实验：人工混合矿浮选实验结果表明,辛基羟肟酸的捕收能力和选择性都优于油酸,辛基羟肟酸-油酸混合捕收剂的浮选性能优于辛基羟肟酸。实际矿石的开路、闭路实验也印证了这一结论。更多还原

【Abstract】 In this paper, seven hydroximic acids collectors were designed and synthesized. By means of micro-flotation tests of pure minerals, the flotation performances of six tertiary amines on diaspore and kaolinite were investigated and figured out. Using the measurements of zeta-potential and FT-IR, the calculations of solution chemistry and quantum chemistry, and the simulations of molecular dynamics, the interaction mechanisms between hydroximic acids and minerals were studied and discussed. The main contents were briefly summarized as follow.(1) When being ground to particles, the liberation of diaspore takes place mainly along the (001) crystal planes, breaking Al-O bonds with high energy and stronger hydrophilicity. The liberation of kaolinite takes place along (001) completly, and along (110) and (010) planes incompletely. Besindes the Al-O bonds whit high energy, there are also the Si-O bonds on these liberation surfaces, which also exhibited the strong hydrophilicity. The surface charging mechanism of diaspore and kaolinite is similarly controlled mainly by the ionization of the surface O-H groups, and this part of charge is dominated by the pH of the pulp. In addition, the isomorphic exchange of kaolinite surface ions is responsible for the permanent negative charge of (001) planes.(2) Under the aim of enhancing the collecting power and selectivity of new collecters on kaolinite, based on the basic structure of flotation reagents and surface characteristics of diaspore and kaolinite, O atom was determined to be the bonding atom of the polar group of new collectors, the polar group was determined to be the Hydroxyl oxime group (-CONHOH). Norpolar group were included, benzene rincycloalkyl, alkyl grou, and the carbon chain lenth of norpolar group were6-9. By using grease, hydroxylamine hydrochloride and formic acid as raw materials, and seven hydroxamic acids were synthesized. The synthetic yield of hydroxamic acid is considerable high, and near all these amines have the purity of more than90%.(3) Flotation of monomineralsFrom the flotations of series of hydroxamic acid, the collectivity of series hydroxamic acids to diaspore in an incremental sequence was shown as follows:Benzyl hydroximic acid<amylic hydroximic acid<heptylic hydroximic acid<sodium oleic acid<octylic hydroximic acid; while the incremental sequence of the colleting power to kaolinite was like this:benzyl hydroximic acid<amylic hydroximic acid<heptylic hydroximic acid<octylic hydroximic acid<oleic acid. The octyl hydroxamic acid, used as collector of bauxite, had more collecting powers and selectivity than the oleic acid.Depressors of NaSiO3, Na4P2O7·10H2O, Na2SiF6and (NaPO3)6had little affect on the recovery of the diaspore, while the can restrain kaolinite effectively, and (NaPO3)6perform excellently.Combination reagents of octyl hydroxamic acid and oleic acid could improve the recovey of the diaspore significantly, when the ratio of the octyl hydroxamic acid was60%, and the best reagent sequence was reagent added with the mixture reagent.(4) Action mechanism of hydroxamic acid on diaspore and kaolinite:Hydroxamic acid reacts on diaspore and kaolinite by chemical bond. Hydroxamic acid anion reduced the Zeta potential on the minrerals. The quality of adsorption on diaspore beloned to multi-layer adsorption was more than on the kaolinite, whinch beloned to single-layer adsorption. From the calculation results, different nonpolargroups affected the charge of the O atom littlly to the hydroxamic acid and hydroxamic acid ion, While which affected the (EHOMOo-ELUMO) and the chemical reactivity in the order of benzohydroxamic acid>cyclohexane hydroxyl oxime acid-heptane hydroxyl oxime, hydrophobic ability in the order of heptane hydroxyl oxime>cyclohexane hydroxyl oxime acid> benzohydroxamic acid.(5) Experiment flotation of manual blend mineral and bauxiteThe experiment flotation with manual blend mineral show the collecting ability and the selectivity in the order of combinations of octyl hydroxyl oxime acid and oleic acid> octyl hydroxyl oxime acid> oleic acid, and the same conclusion all got in open and closed-circuit flotation experiment on bauxite.更多还原